Fastcoin's Block Index -
This is a handy way to select and download individual files to import into your client.
For example, if you already have part of the blockchain and want to snag some of the newer files, you can do so instead of having to sync from other nodes.
If you haven't yet synchronized your client, you will want to use the bootstrap.dat file instead.
Be sure to run your client with -reindex -dbcache=1024 after placing the blk*.dat files in your /blocks/ folder.